1. Field of the Invention
The present invention relates to a polisher for polishing a repair surface to a predetermined shape and a ground paper for polishing to be used for polishers.
2. Description of the Related Art
As for the procedure of repairing scratches and depressions on the coated surface of a vehicle such as an automobile, as shown in FIG. 21, a primer 51, a surfacer 52 and a paint 53 formed on a steel plate 50, are first removed and a depression is filled with a slightly excessive amount of putty P.
As shown in FIG. 22, the surface filled with the putty 1 (damaged portion) is polished to be flush with the surface of the body. In this step, coarse-grained to fine-grained sandpapers are used to polish the surface P1 filled with putty into flat. It is not too much to say that the workmanship of this step determines final repair. Note that the surface P1 filled with putty may be simply referred to as xe2x80x9cputty surface P1xe2x80x9d or xe2x80x9crepair surface P1xe2x80x9d in the following description.
In this polishing step, to reduce time and labor for this polishing, a mechanical sander 100, which is powered by compressed air or electricity, is used. This sander 100 has a movable portion 55 which makes a predetermined motion such as reciprocation or circular motion along the repair surface and a polisher 54, held by the movable portion 55, for polishing the repair surface P1. Note that a polishing surface opposite to the repair surface P1 of the polisher 54 is a flat surface and sandpaper (ground paper) which is an abrasive is affixed to the flat surface.
To use this sander 100, the sander 100 is held by both hands and the polishing surface of the polisher 54 provided on the sander 100 is applied to the repair surface P1 for polishing. Since the polishing surface in contact with the repair surface P1 is flat, the repair surface P1, which is a convex surface, can be polished flat by using this. However, when the repair surface P1 was actually polished, it could not always be polished flat.
The reason for this is that the polishing surface of the polisher 54 is deformed by convex and concave portions formed on the putty surface by the impressions of a trowel used to fill the putty P, thereby impairing flatness. Therefore, it takes much time to obtain a well polished surface and the contact pressure of the polisher 54 against the putty surface P1 must be finely controlled, which requires the skill of an experienced engineer.
To overcome this inconvenience, therefore, polishing has been conventionally made based on the following polishing theory. The polishing theory is that point polishing for polishing only convex portions of the uneven surface formed by the impressions of the trowel with a small polishing area is first made on the putty surface P1 repeatedly to make the putty surface P1 a gently rolling surface as a whole. Subsequently, face polishing is made on the entire putty surface P1 (rolling surface) from which the convex portions of the uneven surface have been removed with a large polishing area.
Thus, by changing the polishing area stepwise, the putty surface P1 having convex and concave portions formed by the impressions of the trowel or the like can be polished flat. When point polishing is carried out continuously, this results in linear polishing. That is, face polishing is carried out after linear polishing substantially.
Stated more specifically based on the actual polishing method, only an edge portion 56 (corner edge portion) of the polisher 54 held by the sander 100 is applied to the repair surface P1 as shown in FIG. 22 to carry out linear (point) polishing. Like this, when the edge portion 56 of the polisher 54 is used, the contact surface between a convex portion on the putty surface P1 and the polisher 54 becomes linear (point) and the convex portions can be polished one by one.
Subsequently, the putty surface P1 is polished flat by linear (point) polishing using the edge portion 56 by operating the sander 100 such that the entire polishing surface of the polisher 54 comes into contact with the putty surface P1 whose convex and concave portions have been polished. Since convex and concave portions formed on the putty surface P1 by the impressions of the trowel or the like have already been removed by linear polishing as described above, the putty surface P1 can be polished flat without impairing the flatness of the polishing surface of the polisher 54.
Thus, a flat and well-polished surface can be easily obtained without using advanced skill theoretically. In addition, as the above polishing theory is a rational technique for obtaining a flat polished surface, a well-polished surface can be obtained within the minimum time.
However, at the time of polishing using the edge portion 56 of the polisher 54, the contact area of the polisher 54 with the repair surface P1 is extremely small as a matter of course and the stability of the polisher 100 is impaired. Therefore, to obtain a well polished smooth surface, an operator must hold the sander 100 (polisher 54) at an appropriate angle with respect to the putty surface P1, thereby requiring advanced skill in fact.
Further, there arises a problem in that the sandpaper of the edge portion 56 wears away quickly. This is a phenomenon that is often seen in the sander 100 for polishing the putty surfer P1 in a short period of time.
The present invention has been made in view of the above, and therefore, an object of the present invention is to provide a polisher which can polish a repair surface flat by simple operation within a short period of time. Also, an object of the present invention is to provide a polisher in which local excessive abrasion of the sandpaper can be suppressed. Also, an object of the present invention is to provide a ground paper for polishers with which working efficiency thereof can be enhanced.
According to a first aspect of the present invention, there is provided a polisher, comprising: a substrate portion 30 for holding an abrasive on a surface opposite to a repair surface; a holding plate 2 provided in parallel to the substrate portion 30 with a predetermined space therebetween; and elastic members 3 interposed between the substrate portion 30 and the holding plate 2, wherein: the substrate portion 30 has a first face plate portion 4 fixed to the above holding plate 2 with a predetermined space therebetween and second face plate portions 5 which are connected to end portions of the first face plate portion 4 and are rotatable about connection lines as axes, connecting them and the first face plate portion 4; and the second face plate portions 5 is provided rotatably in a predetermined range from a position where they become flush with the first face plate portion 4 in a direction that they approach the holding plate 2.
According to the polisher of the present invention, firstly, concave and convex portions formed on a repair surface by the impressions of a trowel or the like are polished with a small polishing surface consisting of only the second face plate portion and then polished with a large polishing surface consisting of the second face plate portions and the first face plate portion. That is, point polishing is carried out with the second face plate portion, and then face polishing is carried out using the first face plate portion and the second face plate portions, simultaneously.
Thus, unlike polishing using an edge portion, a stable operation feeling is obtained in spite of point polishing as the polisher is in face contact with the repair surface. Therefore, the repair surface can be polished flat with simple operation without requiring advanced skill. Sandpaper (ground paper) held on the polishing surface of the polisher is in face contact with the repair surface. Therefore, local excessive abrasion of the sandpaper can also be suppressed.
In this case, the second face plate portions 5 are desirably urged from the holding plate 2 side by the elasticity of the elastic members 3 located between the holding plate 2 and the second face plate portions 5 in a direction that they become flush with the first face plate portion 4.
In this case, the contact pressure of the second face plate portion against the repair surface is maintained at an appropriate level by using the elasticity of the elastic members. Therefore, a stable operation feeling is obtained at the time of polishing using the second face plate portion, thereby making it possible even for an inexperienced person to obtain a well-polished surface easily. Further, when an external force applied to the second face plate portion is removed, the surfaces of the second face plate portions and the surface of the first face plate portion become flush with each other, an operator can polish with the entire surface of the substrate portion without exchanging the polishing surface.
Also, the present invention may take a structure in which the first face plate portion 4 and the second face plate portions 5 each may be formed rectangular, and the long sides of the second face plate portions may be connected to the respective long sides of the first face plate portion 4. In this case, the second face plate portions 5 connected to the respective long sides of the first face plate portion 4 are preferably provided on both of the long sides of the first face plate portion 4.
In this case, the edge portion of the polisher corresponds to the second face plate portion, thereby being capable of linear-polishing using the second face plate portion, which is similar to the polishing in the prior art using an edge portion. When the second face plate portions are provided on the respective long sides of the first face plate portion, operation efficiency is improved without limiting the operation direction of the polisher.
Note that the surface area of each of the second face plate portions 5 is preferably made smaller than the surface area of the first face plate portion 5. In this case, the first face plate portion which does not move with respect to the holding plate contacts the repair surface in a wide range. Accordingly, the stability of the polisher improves at the time of face-polishing using both the first face plate portion and the second face plate portions.
Further, the second face plate portions 5 preferably have flexibility in a direction perpendicular to the longitudinal direction of the second face plate portions 5. In this case, preferably, a plurality of elastic members 3 are provided in the longitudinal direction of the holding plate 2 at predetermined intervals, and the second face plate portions 5 having flexibility are supported by the plurality of elastic members 3.
In this case, the second face plate portions are bent along the swelling of the entire repair surface so that concave and convex portions formed by the impressions of a trowel or the like on the swelling of the repair surface can be caught without fail. Note that when the second face plate portions are supported by the plurality of elastic members, the number of the elastic members is suitably selected to obtain desired flexibility easily.
Further, the movable range of each of the second face plate portions 5 can be set to a range from a position where it becomes flush with the first face plate portion 4 to a position where part of the second face plate portion 5 comes into contact with the side edge of the holding plate 2. With this, the movable range of the second face plate portion is limited to a desired range. Accordingly, when an inexperienced person operates the polisher within the movable range, a well-polished surface can be easily obtained.
The holding plate 2 can be attached to and detached from the movable portion 55 of a sander 100 having the movable portion 55 which can make reciprocation along the repair surface. In this case, there are exemplified as the mechanical sander a double action sander, straight sander, and the like. Note that the polisher of the present invention can be set on not only a mechanical sander but also a manual sander having a holding portion such as a grip for manual polishing.
According to a second aspect of the present invention, there is provided a ground paper 1 for polishing which is used for the above polisher, wherein the ground paper 1 is adhered to a surface facing the repair surface of the substrate portion 30, and a plurality of through holes 31 are formed in the ground paper 1, some of the through holes being located on the boundaries between the first face plate portion 4 and the second face plate portions 5.
Some of the through holes 31 can be made screw holes for attaching the ground paper 1 to the first face plate portion 4. Also, it may employ a structure in which dust collection passages 13 may be formed in the first and second face plate portions 4 and 5 at positions corresponding to the through holes 31 of the ground paper 1, and a dust collection means 3 may be connected to the dust collection passages 13.
In addition, the through holes 13 located at positions corresponding to the boundaries between the first face plate portion 4 and the second face plate portions 5 may be provided at positions for dividing the longitudinal direction of the ground paper 1 into almost three sections.
The through holes 13 located in the first face plate potion 4 may be provided at positions for dividing the longitudinal direction of the substrate portion 30 into almost 4 to 8 sections.
The dust collection means may be connected to a suction device using negative pressure as a suction source. In this case, dust generated in a gap between the repair surface and the substrate portion by polishing is sucked from the dust collection passages 13 and introduced into the suction device 33 having a negative pressure source efficiently.
Suction is carried out from the through holes 31 formed in the ground paper 1. Some of the through holes 31 are located at the boundaries between the first face plate portion and the second face plate portions, with the result that high dust collection efficiency may be obtained.
The reason therefor resides in that, even when either one of the face plate portions is contacted to the polishing surface, the other face plate portion floats from the polishing surface and dust can be collected powerfully from the floated portion because the boundaries between the first and second face plate portions 4 and 5 are angled.